Some people eat, sleep and chew gum, I do genealogy and write...

Friday, April 22, 2016

Digging into DNA

As I have been mentioning recently, I am investigating the relationship of DNA to genealogical research. There is no doubt that some very prickly research issues can be resolved or measurably addressed by DNA testing. But so far, I am still very much of the opinion that without more than adequate  and serious "paper" research, DNA testing is little more than a novelty. Learning that I have a certain possible percentage of relationship to a particular haplogroup may incentivize me to do some research, but otherwise, personally, I don't see the point.

Now by saying that, some will immediately become defensive and be compelled to relate how their personal DNA test changed their entire life and challenged their live view, but even if I were to take several DNA tests, I would not be expecting to obtain any particularly useful information absent some specifically designed and documented problem that was being addressed.

I can't keep from making analogies to other areas of my experience. Most people in the United States either own a car or use public transportation of some kind. However I am sure that very, very few people who are traveling around on the freeways today could explain the inner workings of an internal combustion engine. This lack of understanding about the internal workings of their cars' engines does not stop them at all from driving around. I am also aware that many people do not understand even simple concepts such as "miles per gallon of gas" or whatever. This does not stop them from using the machines for productive purposes. The same things could be said about computers.

In fact the time when computers were being introduced is a great analogy to the present state of DNA. When I first began selling computers back in 1982, we spent a lot of time explaining to people "how they worked." We were all caught up in bits and bytes and RAM and other technical stuff. Granted, today, you might still need to be generally aware of some of the specifications of your computer, but how many of us really care what processor it has?

The idea here is that DNA is in the "explain everything in technical terms stage." But what most people want to know is what they are going to get for their money. For example, let's suppose that I find out that I have certain percentage of Scandinavian genetic material, how does that help me read old Norwegian parish registers? Oh, but you say, I am missing the point. No I am not missing the point. If I have documented ancestral relationships to England, I do not need a DNA test to tell me my ancestors came from England. But as I have mentioned in previous posts, there are certain problems that are apparently possible to solve with DNA research assuming I can get the right relatives to agree to be involved in the test process.

For some time now, I have been aware of the International Society of Genetic Genealogy Wiki. Rather than listing a lot of references, I will refer you to the ISOGG Wiki. There are plenty of links to articles galore about genealogy and genetics. But even here, there is a compulsion to explain in beginning terms, the inner genetic workings of DNA testing. Here is a list of some of general questions DNA testing is supposed to address taken from a post on the Wheaton Surname Resources entitled, "Beginners Guide to Genetic Genealogy."
Why would someone want to use DNA for genealogy? There are many reasons but here are a few of the most common:
  • To learn more about one's ancestry
  • To prove that one's family tree reflects one's actual ancestry
  • To prove or disprove the relationship between two people
  • To prove or disprove a theory of where people came from
  • To break down a brick wall in one's genealogy research
  • To find relatives for those that were adopted, gave up a child for adoption or otherwise do not know their ancestry
  • To learn from which ancestor(s) certain traits were inherited
Some of these are laudable goals, but some of them are only possible given my initial assessment of extensive research and the cooperation of the right relatives.

I guess my wrap up question is how consistent would DNA testing be across different companies? I have been hearing reports of people that have taken several tests and gotten disparate results.


  1. I've tested at the 3 major labs: FTDNA, 23andMe, and Ancestry. I ran those results through Gedmatch.

    I'm satisfied that I have goods tests on file with all three labs. The results are not 100% equal. One lab starts testing one chromosome earlier than another Five genes have small breaks in the sequences. I can accept that. Lab errors happen.
    But when the three labs say I share 3587.0, 3587.1 and 3580.3 centiMorgans, I have confidence in their results.

  2. DNA testing for genealogy is not about knowing your haplogroup or getting admixture percentages. The haplogroups relate to deep ancestry. The admixture percentages are more for entertainment value and have little direct relevance to genealogy apart from in some special cases. The results vary from company to company. See my blog post here:

    DNA testing is all about going into a matching database and comparing your results with other people who share your DNA. It's another way of finding your genealogical cousins but you have the bonus of knowing that you have a genetic relationship with them as well.

    If you have a particular research question to be answered then you do need the co-operation of the right relatives. However, it is still possible to take a DNA test just to see what it throws up in the way of matches. An autosomal DNA test is probably the best starting point. DNA testing is just another type of genealogical record. Genealogists normally want to get their hands on every type of record they can find. Each record can provide new insights.

    The industry is still in its infancy so caution still needs to be exercised with the interpretation of results. This applies particularly to autosomal DNA matches with more distant cousins.